If a polygon of $n$ sides has $275$ diagonals,then $n$ is equal to

$A$ system is provided with $50 \ J$ of heat and the work done on the system is $10 \ J$. What is the change in internal energy of the system in joules?

How many main types of muscles are there?

$A$ plane passing through the points $(0, -1, 0)$ and $(0, 0, 1)$ and making an angle $\frac{\pi}{4}$ with the plane $y - z + 5 = 0$,also passes through the point:

$A$ closed hollow insulated cylinder is filled with gas at $0^oC$ and also contains an insulated piston of negligible weight and negligible thickness at the middle point. The gas on one side of the piston is heated to $100^oC$. If the piston moves $5\,cm$,the length of the hollow cylinder is ..... $cm$.

The equation of the line passing through the point of intersection of the lines $x-3y+2=0$ and $2x+5y-7=0$ and perpendicular to the line $3x+2y+5=0$ is: